This invention relates to a motor vehicle axle component and particularly to a hub and bearing assembly having an integral mounting provision for an anti-lock brake system (ABS) sensor.
In recent years, anti-lock brake systems are being found on an increasing number of passenger motor vehicles, including light duty trucks. The ABS detects wheel rotation and acts to relieve braking force applied on the vehicle's wheels to prevent a lock-up condition from occurring. Wheel brake locking is undesirable since it results in longer stopping distances and directional instability of the vehicle. Typical ABS designs employ a sensor at each vehicle wheel subject to ABS control. Sensors can detect wheel rotation using various technologies including slotted disk light sensor devices, inductive pick-ups, Hall effect devices variable reluctance sensors, etc. Signals from the wheel rotation sensors are fed into an ABS computer which modulates braking force.
Present sensors typically use some type of exciter ring, slotted disk, or other component that rotates relative to a sensor in response to wheel rotation. For most sensor types and particularly those employing magnetic field coupling between the sensor and exciter ring it is important to maintain a pre-determined relationship or clearance between the component which rotates with the wheel and the sensor during wheel rotation. Numerous designs for prior art ABS sensors require that the sensor unit be calibrated after the hub and wheel assembly is affixed to the vehicle, which imposes significant cost and labor disadvantages. In view of these disadvantages, a vehicle hub and bearing assembly with an ABS sensor in which the alignment or set-up clearance between the components of the sensor system is accurately established and can be set with little or no post-assembly adjustment.
The present invention is related to a hub and bearing assembly designed for light duty truck application, featuring integrated provisions for the mounting of an ABS sensor. The hub and bearing assembly of the present invention enables the relationship, between an ABS sensor, and an exciter ring to be established very accurately during assembly of the hub and bearing unit. By providing an accurate and small clearance between the sensor and exciter ring, a higher electrical output for the sensor is provided. This clearance is set during assembly of the hub and bearing unit and later adjustment is unnecessary. The configuration of the present invention also reduces the number of separate assembled components which affect the radial clearance and relationship between the exciter ring and sensor.
The features of the present invention are achieved through a design feature affixing the exciter ring directly to the rotating hub of the assembly, and attaching the sensor directly to the mounting flange of the bearing pack unit which is mounted to a suspension component.
The hub and bearing assembly of the present invention is a specific improvement over one of assignee's own prior art designs. In that prior art assembly, the ABS sensor was mounted to a separate sensor plate which was attached to the bearing mounting flange. This additional sensor mounting plate component imposed the requirement that an additional part must be manufactured and assembled onto the bearing mounting flange and further complicated the process of alignment and controlling the positioning of the sensor during use.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.